SiPM based smart pixel for photon counting integrated streak camera

A Macropixel for photon counting integrated streak camera has been developed in a 180nm standard CMOS process. It includes a 4×4 array of Single Photon Avalanche Diodes (SPAD) acting as a small and smart SiPM (Silicon Photo Multiplier), a unique quenching circuit and a 16 bits memory for smart pixel operation. The total Macropixel size is 32×314 µm
²
, with a sensitive area size of 32×32 µm
²
. The SPAD pitch of 8 µm makes possible to use the standard micro-lens option proposed by the image sensor process and thus to increase the fill factor from the actual 7% up to nearly 100%. Thanks to the embedded memory, each SPAD can be individually enabled or disabled in order to reduce the dark count rate and consequently improve the signal to noise ratio.